Electbic begtxlating-rheostat



L. BOOTHMAN. ELECTRIC REGULAHNG BHEOSTAT.

APPLICATION FILED MAH- 4, 1915.

Patented Aug. 31, 1920.

2 SHEETS-SHEET I.

INVENTOR WITNESSES: 544M [aw/ewe 3001 9014 ATTORNEY BOOTHMAN.

ELECTRIC REGULATING RHEOSTAT.

APPLICATION mm mm. 4, m5.

1,351,019. Patented Aug. 31,1920.

2 SNEETS-SHEET 2.

WITNESSES INVENTOR r M [aw/ 70a BMffi/mn ATTORNEY UNITED STATES PATENT OFFICE.

LAWRENCE BOOTHMAN, OF MANCHESTER, ENGLAND, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND UFACTURIRG.COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRIC REGULATING-RHEOSTAT.

To all whom it may concern:

Be it known that I, LawnnNon Boo'rHMAN, a subject of the King of Great Britain, and a resident of Manchester, in the county of Lancaster England, have invented a new and useful Improvement in Electric Begulating-Rheostats, of which the following is a s ecification.

y invention relates to electric rheostats, and it has foritsobject to provide an Pr h st o v t e in s mpr natw distinct, h ast i e n s, ne, whi h m conveniently .be termed the ,,main rheostat, for varying'themesistancc in, circuit by a series of steps, and the other which will be ein t w e t s. i ts ihdir d n rheostat 'to be alternately cut into and out of circuit between each two successive steps of the main rheostat. T.

My invention comprises a particular construction-in which the .contact'l nembersf of he main and Sab i 1 Q sai' e ns d w zc eea m i a the movable contact members or bridge pieces of the 'rheostats' are operatively fconnected to: a he r a s pu ear ng; s hereinafteriiully set forth.; In the accompanyin drawingsg'Figure 1 is. rear ele'jnitional new, and Fig. 2 is .a side elevational view of a regulating rheostat constructed in accordance with Ithe'present invention, and -F 3 isv a diagrammatic view showing the electric circuits that form a artoithe device shown in Fig.1. k I

he fixed 7 contact :members. of. the main rheostatare indicated, at 1 and those of the s i r g. hwfi a =2, tt r being divided. into two semi-circular sets, .as shown. Between the contact members 1 of the main rheost'ats are .connectediresistance elements 3,, the resistance of each of which equal to the total resistance of a'series of resistance elements 4 with which the subdividing rheostat is provided. 7 The series of resistance elements 4 is divided into substantially equal parts, 44 and 4", which are connected-between the contact. members 2 in Ithe ordinary manner. Concentric with the contactjnembers his a. nearly circular contact memberfi which is connected to the last contact memberqfiiof. thefseries of contact members-1b a conductor 7 and which is alsoconnecte to the first contact member 8 .of the series of contact niembers2 by'a con- ;ductor 9. The first contact member. of the Specification of Letters Patent. Patcn ted Aug. 31, 1920. Application filed Karol 4, 1915. Serial N0. 12,214.

ing shaft 16 having an operating handle 17 l of any suitable description. Near the rear end of the shaft opposite to the handle 17 is secured a cross arm 18 carrying movable contact members 19 that are adapted to successively engage the fixed contact members 2, as the shaft 16 is rotated, thus forming a bridgepiece, as indicated diagrammatically. at 20 in' Fig. 3 Also secured to the shaft 16 is a tw'o armed lever 21 the ends of which are adapted to alternately engage the teeth ;of a spurj gearwheel 22 that is mounted to totateona stud 23 projecting from a bracket which forms part of the frame of the rheostatflAttach'ed to the spur gear wheel 22, asto rotate with it, is a spur gear wheelr25 adapted to mesh with a spur gear vvlieel 2fi that is loosely mounted on the shaft 16 or on a projection of the bracket 24. The spur gear wheel 26 is provided with a projecting arm 27 carrying contact members 28 which are connected together by means of a bridge piece 29 and are adapted, respectively, to move over the fixed contact members 1 and the circular .contact member 5 as the spur gear Wheel 26 is rotated. The contact members 28 and the bridge piece 29are indicated diagrammatically at 30 in Fig. 3 as forming a connection between one of the contact members 1 and the circular contact member 5. v i

As will be seen from Fig. 3, theseries of contact members 2 and the resistance elements 4, which are connected to the contact members 2,are divided into two parts which are connected by the conductor 31, and the contact members 2 are so formed or arranged that, as the bridge iece 20 is moved,

one of the contact members 2, while the other end is moving fromone contact member2tothe next. v

The 0 eration of the apparatus. is as follows: Vl hen all the resistance is in circuit, the bridge piece 30 connects the last contact member 6'01 the series of contact members 1 to the circular contact member 5, and the bridge piece 20 connects the two contact .one of its ends will always e in contact with members of the series 2 which are also connected by the conductor 31. In order to reduce the total'resistance, the handle 17 is rotated to cause the bridge piece 20 to rotate in the counterclockwise direction in Fig; 3 and thus to gradually cut out the resistance 4. When the bridge piece 20 has been rotated through very nearly a semi-circle, it will be in position to connect the contact members 8 and 13, and the lever 21 will engage one-of the teeth of 'the spur gear wheel 22, as shown in Fig. -1 of the drawings. A fill'thel movement'of the shaft in the same direction willcause the brid epiece 20 to again connect the*contact mem ers of the series 2 which are connected by thecon ductor 31,50 that the whole oft-he resistance 4 will be=cut into circuit again. At the same time, the spur gear wheel, together with the spur ear wheel 25,'--w"ill be partially -rotated' y reason of the engagement between.

the lever 21 and the gear wheel-22, which will cause the'spur gear wheel '26 to rotate in a counter-clockwise direction to move the bridge piece =30-from the contact member 6 to the next contact member, and-.tliereby to cutout the dim sectioneffthe resistance 3. A further rotati-ve =inovement of the bridge piece 20through a -'semi-circ'lef'wi'll,' as before, gradually out out the whole of the resistaneeld and -at the end, *a'nother' move ment'of the=bridge piece 30 will becaused, which will cut out the next section of the resistance 3, while the resistancel is rein sertedu It will be readily =-understood that rotative movement of the handle 17 in the other direction will "-result'in' increasing the amount ofresistance'in place-of diminishingrit.

he apparatus, as will be-seen'in Fig. 2, is intended to be mounted on a switch-board panel 32-by means of the supporting bolts 33,'its simple and compact shape being very well-adapted for this purpose. The apparatus may, however, be used as an ordinary rheostat, in which, case the operating "hair dle is preferabl provided on what has been referred to, as e rear end instead of-b in placed infront of-t'he switchboard, as'shown.

I claim'as my invention 1 1, A rheostat for electric circuit control comprising a main series of rheostat elements, a subdividing rheostat associated therewith, contact members adapted to progressivel "engage the said main and subdividing r eost'ats, and gearing oi-operating the said contact members .intimed relation to each other, said gearing comprisin a gear wheel carrying the contact member belonging to the main rheostat, a second gear wheel meshing with the said contact-carrying gear wheel, a third ear wheel adapted to rotate in unison with t e said second gear wheel, and a lever secured to move in unison with the contact member belonging to the subdividing rheostat and adapted to pcriodically engage the said third ,gear wheel and to partially rotate the said ,gear wheel at each such engagement.

2. A rheostatdor electric circuit control comprising a main series of rheostat elements, a subdividing rheostat associated therewith, contact members adapted to progressivelyengageithe said main and subdividing rheostats, and gearing for operating the said contact members in=t imed relation to each other, said gearing comprising-age wheel carrying the contact member belonging to 'the'main-rheostat, a second gear wheel meshin g "with the said contact-carrying' gear wheel, a third gear wheel 'havin a relatively small number'of teeth and a ap'ted tore tate in unison with the said second gear wheel, 'anda lever adapted to rotatecoaxially with the 'said "contact carrying gear wheel andinimison with the contactfliem ber belonging to'the subdividing rheostat and also adaptedto' eriodicallyl engaget hc said third gear -whee and to partiall-y'i'otate the said gear wheel at each such ngeige ment, whereby the contact member belonging to the -1'na'in rheostat is advanced one step after each complete movement-of the contact member belonging tothe- 'subdivid ing rheostatj" V '3. rheostat -for electric-circuit control comprising a series'of "rheostat elements, a subdividing rheostat divided into two parts associated therewith, eontactme nbers adapted to rogressively engage the" said main and su dividin rheos'ta ts,thecontact member for said su dividing rheostat engaging both ofsaid parts, and means for operating said contact members in timed relation to each other.

4; A rheostat 'forelectric-circuit control comprising a substantially circular series 'of main rheostat elements, a subdividing rheostat concentrically dis osed the'said series of elements,sa'i' subdividing" rheostat being divided into two semi-circular parts connected in circuit with each other, contact members adapted to progressively "enga' c said main and subdividin' r'he'ostats, e contact member for said sli dividing-rheostat engaging both of said semi-circular parts, and means "for o eratingfsaid contact members inttimed relatlon to each other;

5. A rheostat provided with two'seriesof stationary contact members, resistance elements i connecting the members of each series, the"contact members of-one of'said series bein divided intojtwo semi-circular sets, move; 1e contact members adapted to progressively engage said stationary contact members, the movable contact member for said divided series engaging "*bothbf said sets and engaging a contact member of one of said sets w ile'moving between-contact membersof said other set, and "means for operating said movable contact members in timed relation to each other.

6. A rheostat comprising a main resistor and a plurality of subdividing resistors, means for short-circuiting said main resistor, means for simultaneously short-circuiting corresponding portions of each of said subdividing resistors and means for effecting the operation of said first-named means after every complete operation of said second-named means.

7. A rheostat comprising a main resistor and a pair of auxiliary resistors, a series of nearly circular stationary contact members connecting the terminal oints and intermediate points of said mam resistor, a plurality of sets of stationary contact members concentrically disposed with respect to said series of contact members connecting the terminal points and intermediate points of said auxiliary resistors, a nearly circular stationary contact member concentrically disposed with respect to said other contact members, means connecting one of the terminal contact members of said series to said nearly circular contact member, means connecting said nearly circular contact member to one of the terminal contact members of one of said sets, means connecting the other terminal contact member of said one set to one of the terminal contact members of said other set,a movable contact member having two portions for respectively engaging the contact members of each of said sets so as to simultaneously short-circuit corresponding portions of each of said auxiliary resistors, a movable contact member having two portions for respectively engaging the contact members of said main resistor and said nearly circular contact member, and means for moving said second-named movable contact member from engagement with one of the contact members of said main resistor into engagement with a succeeding contact member of said main resistor after every half revolution of said other movable contact member.

In testimony whereof I have hereunto subscribed my name this eleventh day of February, 1915.

LAWRENCE BOOTHMAN.

Witnesses:

J. S. PEoK, GEORGE COWLEY. 

